LTE in Sweden – Part 4 – Carrier Aggregation

As I pointed out in previous posts on LTE in Sweden, using several different LTE channels (carriers) is now becoming the norm rather than the exception. Telenor/Tele2, for example, are on-air in 4 different bands at the same time.  Good for you if you have a recent product that supports LTE-Advanced Carrier Aggregation. While CA is great for advertising top speeds, it is much more useful in practice for another purpose.

Especially south of Göteborg in a rural area I noticed that in the evening, throughput of my Samsung S5 that does not yet support Carrier Aggregation was significantly reduced. While during daytime I could easily get download speeds of 40+ Mbit/s, I was down to 5-6 Mbit/s in the evening on a 20 MHz carrier in the 2600 MHz band. Looks like there’s a lot of load on the system.

So with carrier aggregation, users do not have to be distributed among the different channels (more about that in a separate post) but can use several carriers simultaneously. At the moment flagship devices support the aggregation of 2 carriers and the very latest ones come with support for 3. In this rare case, network operators with 4 carriers on air could use even more. For once, networks are ahead of devices (although I would guess the networks themselves don’t yet have the software to aggregate 4 carriers).

And a final thought: As Hutchison 3 has deployed LTE FDD and TDD (see part 3), it’s great that the latest flagship devices have also implemented FDD-TDD LTE carrier aggregation. And obviously, TDD-TDD carrier aggregation also doesn’t hurt as Hutchison 3 has already deployed two 20 MHz TD channels in Stockholm.